Texas Power Grid Weathers Winter Freeze


The Electric Reliability Council of Texas reported that it did not need to cut power to any part of the state during the 48-hour freeze last week, after weatherizing the power grid in response to last year’s outages.

According to reports, the grid topped out at about 69 gigawatts on Feb. 4 and 63.4 gigawatts on Feb. 5, with demand falling short of 73 to more than 75 gigawatt projections and never nearing the record levels seen during last year’s winter storm.

“The Texas electric grid is more reliable, and more resilient than it has ever been,” Gov. Greg Abbott said during a briefing on Feb. 4 at the state’s emergency operations center in Austin.

“We believe the weatherization and our preparations have been extraordinary and are pretty successful,” said ERCOT’s interim CEO Brad Jones. Jones also noted that no significant outages at power plants were reported during the storm, and the amount of power plants forced offline remained below ERCOT projections.

On Feb. 2, ERCOT issued a Winter Weather Watch through Feb. 6, forecasting high energy demand and taking action ahead of the expected increase to ensure grid reliability.

“ERCOT is using all the tools available to manage the grid effectively during this winter weather,” said Jones in the release. “ERCOT will deploy all the resources and aggressively implement the tools available to us to manage the grid reliably during this winter weather.”

According to ERCOT, several reforms were implemented to increase the reliability of the Texas grid:

  • Inspected generating units and transmission and distribution facilities for weatherization to comply with new PUC requirements;
  • Requiring CEO attestations of weather readiness;
  • Taking a more conservative approach to operating the grid;
  • Assessing on-site fuel supplies; and
  • Performing unannounced testing of generation resources.

In January, ERCOT released its final winter weatherization readiness report with the Public Utility Commission of Texas. It showed that 321 out of 324 electric generation units and transmission facilities fully passed inspection for new winterization regulations.

Of the onsite inspections, 302 represented 85% of the megawatt hours lost during Winter Storm Uri due to outages and 22 transmission station facilities. According to the report, three resources were identified for further review but remain operation, only representing approximate 0.4% of the total fleet.

“We are confident these 321 inspected facilities either meet or go beyond the new requirements from the Commission and we will continue to work with the other 3 facilities to ensure they correct remaining deficiencies,” said Woody Rickerson, ERCOT Vice President of System Planning and Weatherization. “Our teams spent thousands of hours preparing for and conducting these 324 on-site inspections to ensure the electric grid is prepared for winter.” 

Wind energy performed above expectations, pushing 70% more energy than expected into the grid at times.

However, in an interview, Doug Lewin, an energy consultant and head of Stoic Energy, said the grid wasn’t truly tested during this storm.

“The grade I would give this is incomplete,” he said. “It’s just a very low bar to clear.”

Concerns also still remain about natural gas supply and infrastructure during these freezes.

“Still flashing red lights on the gas supply system,” Lewin said. “If the storm have covered the whole state, and if we had freezes in both the Permian and the Eagle Ford Shale, we might’ve seen 40, 50, 60 percent reduction drops like we saw one year ago.”

Natural gas producers were not required to winterize and saw production drop 20% when the temperatures dropped, according to reports.

What Happened

On Feb. 14, 2021, ERCOT asked consumers and businesses to reduce their electricity use due to anticipated record electric use during the impending Texas freeze.

"We are experiencing record-breaking electric demand due to the extreme cold temperatures that have gripped Texas," said ERCOT President and CEO Bill Magness said at the time. "At the same time, we are dealing with higher-than-normal generation outages due to frozen wind turbines and limited natural gas supplies available to generating units."

The next day, ERCOT issued an Energy Emergency Alert as outages began increasing, citing “extreme weather conditions caused many generating units – across fuel types – to trip offline and become unavailable.”

The winter storm left 4.8 million homes and businesses in Texas without electricity, heat and clean water for several days in subfreezing temperatures, and more than 200 people died.

In an interview with NBC News, Curt Morgan, CEO of Texas’ largest power generator Vistra Corp., said he’d never seen anything like it in his 40 years in the industry.

In response to the disaster, Gov. Abbot signed legislation into law in June to prepare, prevent and respond to weather emergencies and power outages. Senate Bill 3 required weatherization upgrades for power generators and transmission lines. The Texas Railroad Commission and ERCOT would reportedly conduct inspections of facilities and could penalize for up to $1 million if failed.

However, the bill did receive criticism as it did not provide direct aid to individuals impacted by the storm or fund backup power generation for critical facilities such as hospitals.

The bill also outlined requirements to study and implement a power outage emergency alert system for the state in the event of weather emergencies, as well as provide disaster preparedness education.

However, Morgan said one of the bigger issues is the supply of natural gas, and if another freeze hits this winter, “the same thing could happen.” During the storm, 14 Vistra power plants that run on gas ran without enough fuel. After spending $1.5 billion for what gas they could purchase, the facilities were reportedly only able to run at 30% capacity.

ERCOT added that at least 20% of the outages the week of the storm were due to power plants’ not getting enough gas, reportedly due to outages, frozen equipment and weather conditions.

Located on an island, the Texas grid isn't connected to the country’s two major power grids, leaving federal agencies unable to create regulations. With decisions over the grid left up to state lawmakers, a proposal by the Texas Railroad Commission issued in September laid out a timeline to identify, map and impose weatherization mandates for gas producers by early 2023.

Companies are reportedly able to opt out of “critical infrastructure” classification to avoid the weatherization requirements.

Electric companies, including Oncor, AEP Texas, CenterPoint and Texas-New Mexico Power Co., filed a comment with the commission arguing that the proposed rule was too vague and that it “does not provide information electric utilities will need in order to efficiently and effectively incorporate natural gas facilities into their respective” emergency plans.

In October, the Public Utility Commission of Texas, which is reportedly designing the weatherization requirements for power plants, passed a short-term rule for companies to submit a report to regulators by Dec. 1 on how they’re preparing their plants for winter. Requirements included preparations for cold temperature operations, fixing any known issues from the previous winter season and training on winter preparedness.

FERC Winterization Report

The Federal Electric Reliability Corporation released a report in November on the impact of the February winter storm on the Texas electrical system. The report outlined the need to strengthen rules for cold weather preparedness and coordination to prevent future blackouts from happening.

Details in the report cite that a combination of freezing issues and fuel issues caused unplanned outages:

  • 81% of freeze-related generating unit outages occurred at temperatures above the units’ stated ambient design temperature;
  • 87% of unplanned generation outages due to fuel issues were related to natural gas, predominantly related to production and processing issues, while 13% involved issues with other fuels such as coal or fuel oil; and
  • Natural gas fuel supply issues were caused by natural gas production declines, with 43.3% of natural gas production declines caused by freezing temperatures and weather, and 21.5% caused by midstream, wellhead or gathering facility power losses, which could be attributed either to rolling blackouts or weather-related outages such as downed power lines.

The FERC report includes 28 formal recommendations to prevent an outage recurrence this year, such as old weather impacts on mechanical and electrical components, utilization of weather forecasts to better predict electric demand, increasing the ability to rotate rolling blackouts and additional study of the ERCOT system’s reliability issues.

The full report can be viewed here.


Tagged categories: Federal Energy Regulatory Commission (FERC); Health & Safety; Health and safety; Infrastructure; NA; North America; Oil and Gas; Power; Power; Power Plants; Program/Project Management; Safety

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